1. Field
Embodiments relate to a terminal unit for a secondary battery and a method of manufacturing the same.
2. Description of the Related Art
Secondary batteries are rechargeable batteries widely used in portable electronic devices, e.g., mobile phones, notebook computers, and camcorders. A secondary battery may include a case having an open portion, an electrode assembly accommodated in the case and including a positive electrode, a negative electrode, and a separator wound in a jelly-roll shape, and a cap assembly covering the open portion of the case. In addition, a current collecting plate may be disposed on an end of the electrode assembly. The current collecting plate may be electrically connected to a terminal arranged in the cap assembly. Thus, when the terminal of the cap assembly is connected to an external terminal, a current generated in the electrode assembly may be supplied to the external terminal via the current collecting plate and the terminal of the cap assembly.
The terminal unit may include a positive electrode rivet and a negative electrode rivet, which may be connected to the current collecting plate, and rivet terminals coupled to respective positive and negative-electrode rivets to be connected to bus bars. Coupling between the positive or negative electrode rivet and the rivet terminal and between the rivet terminal and the bus bar may be performed by laser welding. However, the positive electrode rivet and the negative electrode rivet may generally be formed of different metals. Thus, if the rivet terminal is formed of a different material from the materials of the positive electrode rivet and/or negative electrode rivet, heterogeneous metal welding may be performed between the electrode rivet and the rivet terminal, resulting in poor weldability.